The present invention relates to a tool assembly constructed for evacuating and charging a fluid receiving system such as a liquid coolant system for an internal combustion engine. This tool assembly is adapted to be connected to an inlet fitting for a radiator of an engine coolant system in place of the radiator cap for first evacuating air and moisture from the system and then charging the system with a predetermined volume of liquid coolant. This invention is an improvement of the dispensing tool assembly disclosed in U.S. Pat. No. 5,560,407 invented by the applicant of the present invention. The improvement of the present invention pertains to an increase in fluid charging flow rate, elimination of sealing member to inlet fitting sticking, and protection of the tool outlet tube during handling.